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possible ez way to lower CYA

a buddy of mine was told this method to lower CYA from a pool store guy.
he says he tried it and it worked. i'm wondering what the experts here think.

CYA is denser than water and settles to bottom of pool when left unstirred.
He said leave the pool off for a day or two then
close the skimmer drains and pull all the water from the pool bottom when you do normal backwashing
(or you could use Waste setting when you have too much water in pool).

So I needed to backwash, so I added a couple inches of water. CYA was at 120.
Then Left pool off for one day. I closed skimmer drains
and pulled about 3 inches of water out via the bottom drain. CYA went to 80.
It then rained two days later and I needed to lower the water another inch or two.
Not wanting to backwash the new Diam earth , I
set the pool to waste, closed skimmers again. Lowered pool about one-two inches.
CYA is now 65. Unbelievable. This is using my kit to measure.

Re: possible ez way to lower CYA

CYA is denser than water and settles to bottom of pool when left unstirred.

If that statement was true, you would never be able to accurately test for CYA as it would be constantly settling. Additionally, if the CYA does not mix evenly throughout the body of water, it would offer no protection from the sun.

Re: possible ez way to lower CYA

I was in a pool product seminar once and the guy doing it said the exact opposite. That CYA stays in the upper foot of water and the fastest way to lower it is to turn off the drain and drain the pool from the skimmers!
Of course this is pure rubbish as is the advice to turn off the pumps and drain from the bottom because "CYA is heavier than water"!
CYA, once dissolved in the water, exists in the form of cyanurate ions and chlorinated isocyanurate compounds, in addition to cyanuric acid. This are ionic species that are dissolved in the water and can not be separated out any easier than say, salt, which becomes sodium and chloride ions in the water.
ANYONE who has had a basic high school chemistry class will understand this.

Re: possible ez way to lower CYA

Originally Posted by waterbear

I was in a pool product seminar once and the guy doing it said the exact opposite. That CYA stays in the upper foot of water and the fastest way to lower it is to turn off the drain and drain the pool from the skimmers!
Of course this is pure rubbish as is the advice to turn off the pumps and drain from the bottom because "CYA is heavier than water"!
CYA, once dissolved in the water, exists in the form of cyanurate ions and chlorinated isocyanurate compounds, in addition to cyanuric acid. This are ionic species that are dissolved in the water and can not be separated out any easier than say, salt, which becomes sodium and chloride ions in the water.
ANYONE who has had a basic high school chemistry class will understand this.

I have had College Prep Chemistry 1 and 2 in High School, plus Chemistry 101 in College, and I have to say that I don't understand it.

Re: possible ez way to lower CYA

Originally Posted by sevver

Originally Posted by waterbear

I was in a pool product seminar once and the guy doing it said the exact opposite. That CYA stays in the upper foot of water and the fastest way to lower it is to turn off the drain and drain the pool from the skimmers!
Of course this is pure rubbish as is the advice to turn off the pumps and drain from the bottom because "CYA is heavier than water"!
CYA, once dissolved in the water, exists in the form of cyanurate ions and chlorinated isocyanurate compounds, in addition to cyanuric acid. This are ionic species that are dissolved in the water and can not be separated out any easier than say, salt, which becomes sodium and chloride ions in the water.
ANYONE who has had a basic high school chemistry class will understand this.

I have had College Prep Chemistry 1 and 2 in High School, plus Chemistry 101 in College, and I have to say that I don't understand it.